The air interface specification for many CDMA transceivers can be quite complex. Most currently available Digital Signal Processors (DSP) that perform to the air interface specification for CDMA systems either consume too much power, or they do not have enough correlation capacity for chip level processing. This is especially important for battery powered devices, since the power consumed directly relates to the battery life and frequency of charging or battery replacement. As the requirements for more and more processing power increase, this problem is compounded. This is also especially true for high frequencies of operation dictated by high data rates, such as those specified for the third generation (3G) and beyond for CDMA, where these issues present significant obstacles to designers. An additional obstacle is imposed if the transceiver is to process multiple users or multiple channels in parallel.
The field of reconfigurable processors is currently undergoing a period of rapid advances. Reconfigurable processors are circuit arrangements containing an array of circuits such as processors, arithmetic logic units (ALU), memory, interfaces, and other logic, digital and/or analog circuits that can be configured to operate in a desired manner under programmed control. Thus, the same circuit can be configured and reconfigured to operate in several ways depending upon the manner in which the circuit configuration is programmed. One popular application for such circuitry is in the field of digital signal processing (DSP). In this field, for example, a reconfigurable processor might operate as a first type of modem in a first environment and a second type of modem in a different environment.
In conventional reconfigurable processors, a single fixed clock is used to control the timing of internal functions. That is, the signal processing data path fabric operates at one fixed internal clock frequency. This can lead to high power consumption for certain DSP applications. This is almost always undesirable, but is particularly bothersome in battery-powered devices whose battery life is dependent upon minimizing excess power consumption.